#include "yaml-cpp/binary.h"

namespace YAML
{
	static const char encoding[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

	std::string EncodeBase64(const unsigned char *data, std::size_t size)
	{
		const char PAD = '=';

		std::string ret;
		ret.resize(4 * size / 3 + 3);
		char *out = &ret[0];

		std::size_t chunks = size / 3;
		std::size_t remainder = size % 3;

		for (std::size_t i = 0; i < chunks; i++, data += 3) {
			*out++ = encoding[data[0] >> 2];
			*out++ = encoding[((data[0] & 0x3) << 4) | (data[1] >> 4)];
			*out++ = encoding[((data[1] & 0xf) << 2) | (data[2] >> 6)];
			*out++ = encoding[data[2] & 0x3f];
		}

		switch (remainder) {
		case 0:
			break;
		case 1:
			*out++ = encoding[data[0] >> 2];
			*out++ = encoding[((data[0] & 0x3) << 4)];
			*out++ = PAD;
			*out++ = PAD;
			break;
		case 2:
			*out++ = encoding[data[0] >> 2];
			*out++ = encoding[((data[0] & 0x3) << 4) | (data[1] >> 4)];
			*out++ = encoding[((data[1] & 0xf) << 2)];
			*out++ = PAD;
			break;
		}

		ret.resize(out - &ret[0]);
		return ret;
	}

	static const unsigned char decoding[] = {
		255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
		255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
		255,255,255,255,255,255,255,255,255,255,255, 62,255,255,255, 63,
		 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,255,255,255,  0,255,255,
		255,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
		 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,255,255,255,255,255,
		255, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
		 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,255,255,255,255,255,
		255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
		255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
		255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
		255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
		255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
		255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
		255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
		255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
	};

	std::vector<unsigned char> DecodeBase64(const std::string& input)
	{
		typedef std::vector<unsigned char> ret_type;
		if (input.empty())
			return ret_type();

		ret_type ret(3 * input.size() / 4 + 1);
		unsigned char *out = &ret[0];

		unsigned value = 0;
		for (std::size_t i = 0; i < input.size(); i++) {
			unsigned char d = decoding[static_cast<unsigned>(input[i])];
			if (d == 255)
				return ret_type();

			value = (value << 6) | d;
			if (i % 4 == 3) {
				*out++ = static_cast<unsigned char> (value >> 16);
				if (i > 0 && input[i - 1] != '=')
					*out++ = static_cast<unsigned char> (value >> 8);
				if (input[i] != '=')
					*out++ = static_cast<unsigned char> (value);
			}
		}

		ret.resize(out - &ret[0]);
		return ret;
	}
}